Recently I got promoted to Lead designer at an Engineering Company, I have a team of 7 that I have working with on different projects, l'm 28(M) & my team mates are approx my age if not older, they're married and settled, but I was appointed as Lead designer, I am having issue with my team members respecting me, one in particular has been very argumentative and rude in front of the team, & I dont know how to take care of this without being rude and argumentative, So much so that I have taken a back having any conversation with the person. I am not a confrontational person and having a hard time dealing with him without involving HR, because that would make me look weak and that I'm not able to handle the job. Please help me with this & how I can approach the issue.